Suitability for swimming

This section provides the latest statistics on the water quality of recreational freshwater beaches (rivers, lagoons and lakes) and coastal beaches.

The ‘Suitability for Recreation Grade’ (SFRG) measures the water quality at recreational freshwater and coastal beaches during the summer months. There are five grades, ranging from very good (suitable for swimming almost all of the time) to very poor (often unsuitable for swimming) [1]. 

Monitored sites tend to be popular swimming spots. Some regions did not provide data (Northland, Auckland, Waikato and West Coast). 

On this page:

Many freshwater sites are often unsuitable for swimming
Most coastal sites are usually suitable for swimming
Map of water quality at freshwater and coastal sites

Many freshwater sites are often unsuitable for swimming

In 2012–2013, 50 percent of monitored freshwater sites were graded as ‘poor’ or ‘very poor’ (103 out of 204 sites). These sites may not always be suitable for swimming, as they are susceptible to faecal contamination. There were some regional differences (Figure 1). 

Figure 1

Most coastal sites are usually suitable for swimming

Generally, coastal sites had better water quality than freshwater sites. Most coastal sites were usually suitable for swimming. 

In 2012–2013, 63 percent of coastal sites were graded as ‘very good’ or ‘good’ (140 out of 221 monitored sites).  These sites were always or usually suitable for swimming.  About 13 percent of coastal sites were graded as ‘poor’ or ‘very poor’.

In 2012–13, there were some regional differences in coastal water quality at monitored sites (Figure 2). 

Figure 2

Map of water quality at freshwater and coastal sites

The map below gives the suitability for recreation grade for freshwater and coastal sites monitored in 2012–2013. 

Figure 3: Recreational beach grades from monitored sites, 2012-2013 

Source: Ministry for the Environment [1]

For more information and to access the original map and data, visit the Ministry for the Environment webpage on suitability for swimming.  

Information about the data

Suitability for Recreation Grade

Source: Ministry for the Environment – Suitability for recreation grade (SFRG)

Suitability for Recreation Grade (SFRG) monitoring data are collected by regional, unitary and district councils, and collated by the Ministry for the Environment.  

In 2012–2013, SFRG monitoring data were available for 204 freshwater sites (including 158 river or lagoon sites and 46 lake sites) and 221 coastal sites.  A number of recreational water sites have not been included in these reported data, including all sites in the Northland, Auckland, Waikato and West Coast regions. SFRGs were not calculated for these sites, due to insufficient or unsuitable data (Ministry for the Environment, 2013a).

The SFRG aggregates five years of data to provide a long-term estimate of suitability for recreation. The SFRG is calculated from two components.

  • The Microbial Assessment Category (MAC) measures the health risk associated with direct contact with water. This is based on indicator bacteria levels in water samples collected weekly over five summers.
  • The Sanitary Inspection Category (SIC) assesses the susceptibility of the water body to faecal contamination, from sources like agricultural runoff, storm water discharges or dense waterfowl populations.

Table 1: Suitability for Recreation Grade (SFRG) matrix  

Sanitary Inspection Category (SIC) Microbial Assessment Category (MAC)
A (low risk) B C D (high risk)
Very low risk Very good Very good Follow up Follow up 
Low risk Very good Good Fair Follow up 
Moderate risk Follow up Good Fair Poor
High risk Follow up Follow up Poor Very poor
Very high risk Follow up Follow up Follow up  Very poor


1. Ministry for the Environment. 2013. Suitability for swimming. Available online: